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Background: Interest in finding efficient ways to remove penicillin allergy alerts has grown as a result of awareness of the considerable excess of false-negative diagnoses in patients with penicillin allergy labels (90%-95%), the poorer course with non-ß-lactam antibiotics, the increase in bacterial resistance, and the fact that these problems can affect up to 20% of the population in some countries. The strategies proposed have generated many publications in countries where the number of allergists to conduct such studies is low. In many cases where delabeling is performed, the risk of ß-lactam allergy is low, and a single penicillin challenge is sufficient to delabel the alert. However, other less "ultrarapid" strategies can be used to administer a ß-lactam during an admission for infection and thus postpone delabeling until traditional drug allergy consultations. However, the definitive withdrawal of ß-lactam alerts is threatened by nonremoval of alerts in electronic health records and by the reactivation or nonsynchronization of alerts between electronic systems at different levels of care. Allergy departments need to reflect on how to implement practices that enable rapid and efficient delabeling of drug allergy alerts, especially in patients with major comorbidities.

Cow's milk allergy can result in anaphylactic reactions. The estimated prevalence of cow's milk allergy in developed countries ranges from 0.5% to 3% at age 1 year. Our objective was to perform a systematic review and, if possible, a meta-analysis to assess the frequency of fatal and recurrent anaphylaxis induced by cow's milk. We searched PubMed/MEDLINE, EMBASE, and the Web of Science for studies that had assessed fatal and recurrent anaphylaxis induced by cow's milk for the population of a country or at least an administrative region. Our review included cohort, cross-sectional, and registry studies that had assessed the incidence or prevalence of recurrent anaphylaxis or the incidence of fatal anaphylaxis due to cow's milk. The pooled prevalence of recurrence (PR) for at least an episode of anaphylaxis was 26.98% (3.85-189.1). Teymourpour et al (Iran) reported the highest PR (53.10%); the two studies with the lowest PR were from France (5.2 and 0.42, respectively) (p < .01). Nine studies on fatal anaphylaxis were selected (41 deaths) and found to be highly heterogeneous (I 2  = 75.9%). Levy et al and Bassagio et al reported the highest incidence rate (IR 0.15 and 0.6 deaths per million persons-year). The PR of anaphylaxis was approximately one quarter of patients with anaphylaxis due to cow's milk, while deaths from anaphylaxis caused by cow's milk were very rare, although some studies report rates as high as 15 times the lowest IR., (© 2023 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Introduction: The drug allergy alert system reduces the frequency of adverse drug events, although it is subjected to collateral effects, since 80-90% of alerts are not real, and a large percentage of alerts are overridden (46.2-96.2%). We reviewed how the alert system is used at University Hospital Fundación Alcorcon (HUFA)., Methods: Data were obtained from the drug allergy alert and the alert overriding notification forms (both in the period 2011-20). We also recorded drug allergy diagnoses at HUFA, drug consumption in primary care in 2016. We calculated the incidence of drug allergy alert activation, temporal trends in use, and correlations between the number of drugs in several datasets., Results: We collected 15,535 alerts. NSAIDs and penicillins were the drugs with the highest number of drug allergy alerts (36.55% and 26.91%, respectively). A correlation was found between the number of drug alerts and the type of drug allergy in HUFA in 2016. Only 6.83% of the alerts were removed, and, of these, 21.77% were reactivated. Approximately 100 overrides were recorded per year from 2016 (6.8% of 8,434 activated alerts during 2014-2020)., Conclusions: The number of drug allergy alerts recorded via the drug allergy alert system of HUFA correlates with the distribution of drug allergy diagnoses in the hospital, although many of the alerts could be false positives (as per current published evidence). We detected a very low frequency of removed alerts (6.83%), a relevant frequency of reactivations (one quarter), and a very low frequency of overrides (6.8%)., (© 2023 S. Karger AG, Basel.)

Introduction: The drug provocation test (DPT) is the gold standard for the drug allergy workup; however, it is not free from severe adverse reactions. Our aim was to obtain robust data that predict a reaction during or after the DPT at the first contact with the patient in the allergy outpatient clinic., Methods: The population of this cross-sectional study comprised all patients undergoing a drug allergy workup (clinical assessment, specific IgE, or skin tests, or DPT) at University Hospital Fundacion Alcorcon in 2016. DPTs were performed until therapeutic doses were reached, and late reactions were checked. The clinical disorders assessed in our study were classified mainly as absence of allergic reactions, morbilliform rash, urticaria, anaphylaxis, and other cutaneous disorders., Results: Physicians from the Allergy Unit programmed drug allergy workups in 977 patients (median age, 52 years; women, 64.54%). DPTs were not performed for 165 drugs involved in the reactions. Patients who did not undergo DPT were older than patients who did (positive or negative) (p = 0.0001). Positive DPT results were detected in 6.00% of DPTs performed, and most were for amoxicillin and metamizole (15-25% each). Multinomial logistic regression showed that positive reactions were more probable after DPT if the same clinical disorder was diagnosed at the first visit, including the episodes not considered allergic episodes (OR = 0.2, <0.01), except for anaphylaxis, which favored not performing DPTs (OR = 11, p < 0.001)., Conclusion: We conclude that clinical practice in the diagnosis of drug allergy in our Allergy Department is safe, without over-diagnosis., (© 2023 S. Karger AG, Basel.)

Background: Fatal anaphylaxis is very rare, with an incidence ranging from 0.5 to 1 deaths per million person-years., Objective: Based on a systematic review, we aimed to explain differences in the reported incidence of fatal anaphylaxis based on the methodological and demographic factors addressed in the various studies., Methods: We searched PubMed/MEDLINE, EMBASE, and the Web of Science for relevant retrospective and prospective cohort studies and registry studies that had assessed the anaphylaxis mortality rate for the population of a country or for an administrative region. The research strategy was based on combining the term "anaphylaxis" with "death", "study design", and "main outcomes" (incidence)., Results: A total of 46 studies met the study criteria and included 16,541 deaths. The range of the anaphylaxis mortality rate for all causes of anaphylaxis was 0.002-2.51 deaths per million person-years. Fatal anaphylaxis due to food (range 0.002-0.29) was rarer than deaths due to drugs (range 0.004-0.56) or Hymenoptera venom (range 0.02-0.61). The frequency of deaths due to anaphylaxis by drugs increased during the study period (IRR per year, 1.02; 95%CI, 1.00-1.04). We detected considerable heterogeneity in almost all of the meta-analyses carried out., Conclusion: The incidence of fatal anaphylaxis is very low and differs according to the various subgroups analyzed. The studies were very heterogeneous. Fatal anaphylaxis due to food seems to be less common than fatal anaphylaxis due to drugs or Hymenoptera venom.

Objective: During its first year, the AWARE study assessed disease activity, patient quality of life (QOL), and treatment patterns in chronic urticaria (CU) refractory to H1-antihistamines (H1-AH) in clinical practice., Methods: We performed an observational, prospective (24 months), international, multicenter study. The inclusion criteria were age ≥18 years and H1-AH-refractory CU (>2 months). At each visit, patients completed questionnaires to assess disease burden (Urticaria Control Test [UCT]), disease activity (7 day-Urticaria Activity Score [UAS7]), and QOL (Dermatology Life Quality index [DLQI], Chronic Urticaria Quality of Life Questionnaire [CU-Q2oL], and Angioedema Quality of Life Questionnaire [AE-QoL]). We present data for Spain., Results: The study population comprised 270 evaluable patients (73.3% female, mean [SD] age, 48.9 [14.7] years). At baseline, 89.3% were prescribed a CU treatment. After 1 year, first- and second-line treatments became less frequent and third-line treatments became more frequent. At baseline, 47.0% of patients experienced angioedema; at 1 year, this percentage had fallen to 11.8%. The mean (SD) AE-QoL score decreased from 45.2 (28.7) to 24.0 (25.8). The mean (SD) UCT score decreased from 7.0 (4.5) to 12.1 (4.1). According to UAS7, 38.2% of patients reported absence of wheals and itch in the previous 7 days at 1 year compared with 8.3% at baseline. The mean (SD) DLQI score decreased from 8.0 (7.4) to 2.8 (4.6). At the 1-year visit, the percentage of patients reporting a high or very high impact on QOL fell from 29.9% to 9.6%., Conclusion: H1-AH-refractory CU in Spain is characterized by absence of control of symptoms and a considerable impact on QOL. Continuous follow-up of CU patients and third-line therapies reduce disease burden and improve patients' QOL.

Background: Penicillin allergy is a common problem in the management of infectious diseases. The aim of this study was to determine the impact of penicillin allergy on length of hospital stay (LOHS) among hospitalized adult patients and on in-hospital mortality at a national level., Methods: A retrospective cohort study of adult patients discharged from the Spanish Hospital System between 2006 and 2015 was conducted using the Minimum Basic Data Set (MBDS). We compared LOHS and in-hospital mortality of adult patients whose records contained penicillin allergy code V14.0 (International Classification of Diseases, Ninth Revision, Clinical Modification) as a secondary diagnosis, with a random sample without such a code., Results: We identified 981,291 admissions with code V14.0, which corresponded to 2.63% of all hospitalizations. Adults patients with a penicillin allergy label were significantly older than patients without such a label, with a median of 70 years (interquartile range [IQR]: 51-80) versus 63 years (IQR: 40-77). The proportion of women and the prevalence of infectious diseases were higher in the group with a penicillin allergy label (61.40% vs. 53.84%; 34.04% vs. 30.01%; respectively). We found a higher median Elixhauser-Van Walraven score in hospitalized patients with an allergy label. The median LOHS for hospitalizations with a penicillin allergy label (5 [IQR: 2-9]) was significantly longer than that in those without such a label (4 [IQR: 2-9]). Multivariate analysis showed an increase in LOHS due to the penicillin allergy label (odds ratio [OR] [95% confidence interval [CI]: 1.061 [1.057-1.065]) and a decrease in mortality in penicillin allergy records (OR [95% CI]: 0.834 [0.825-0.844])., Conclusion: In our study, the prevalence of a penicillin allergy label in hospitalized patients, using the MBDS, is low. Hospitalizations with an allergy label was associated with a longer LOHS. However, penicillin-allergic patients did not show higher mortality rates. Inaccurate reporting of penicillin allergies may have an impact on healthcare resources., (© 2021 S. Karger AG, Basel.)

Background and Objective: Asthma is very prevalent in all grades of severity of anaphylaxis. Asthma and chronic obstructive pulmonary disease (COPD) have been associated with the severity of anaphylaxis. Objective: We carried out a systematic review and meta-analysis to assess the influence of respiratory diseases on the severity of anaphylaxis., Methods: We searched PubMed/MEDLINE, EMBASE, and the Web of Science for observational studies. The target studies were those that compared the severity of anaphylaxis between patients who had or did not have respiratory diseases., Results: A total of 13 studies assessed the severity of anaphylaxis in respiratory disease. Respiratory disease increased the severity of anaphylaxis (OR, 1.87; 95%CI, 1.30-2.70), as did asthma (OR, 1.89; 95%CI, 1.26-2.83). For the meta-analysis of all studies (adjusted and nonadjusted), COPD increased the severity of anaphylaxis (OR, 2.47; 95%CI, 1.46-4.18). In the case of asthma studies, only 1 study assessed the influence of severity of asthma on severity of anaphylaxis., Conclusions: Evidence showing that respiratory disease increases the severity of anaphylaxis is low to moderate, although studies do not usually assess the importance of severity of asthma.

Forensic series on fatal anaphylaxis are scarce, probably because the diagnosis of anaphylaxis is often complex and the incidence is low. We report on the medicolegal, demographic and histopathological characteristics of a series of sudden deaths which were investigated for anaphylaxis at the Spanish National Institute of Toxicology and Forensic Sciences (INTCF) over a 17-year period (1998-2015). A total of 122 undetermined sudden deaths from a high percentage of Spanish regions (81.5% of the total population) were sent to the INTCF with anaphylaxis as the suspected cause of death for histological, biochemical, and medicolegal investigation. Two certified allergists confirmed that 46 of the 122 cases were fatal anaphylaxis. The results indicated a median age of 51 years (IQR = 29) and a male predominance (76%). The main causes of anaphylaxis were drugs (41%), hymenoptera stings (33%), and food (13%). A previous allergic event had been reported in both food anaphylaxis (67%) and drug anaphylaxis (53%). The deaths occurred in health care settings (37%), at home (22%), and outside the home (26.09%). Histopathology data were available for 40 individuals. The most frequent autopsy findings were angioedema of the upper airways (50%), pulmonary edema (47.5%), atheromatosis of coronary vessels (32.5%), and pulmonary congestion (27.5%). Our findings for fatal anaphylaxis indicated a predominance of men, older age (≥50 years) and death in a health care setting (one-third of cases). Previous episodes had occurred in two-thirds of cases of food-induced anaphylaxis and in half of the cases of drug-induced anaphylaxis.

Background: Beta-blockers (BBs) and angiotensin-converting enzyme inhibitors (ACEIs) have been associated with an increased risk and severity of anaphylaxis. However, the evidence supporting these findings is contradictory., Objective: We carried out a systematic review and meta-analysis of studies that assess the influence of BBs and ACEIs on anaphylaxis., Methods: We searched PubMed/MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and the Web of Science for relevant observational studies. We searched for studies where the presence and severity of anaphylaxis were compared between patients taking BBs, ACEIs, both types of drug, or neither type of drug. We performed a meta-analysis using a random-effects model., Results: A total of 21 studies met the study criteria. Of these, 15 assessed the severity and 9 the incidence of anaphylaxis. The studies brought together 22,313 anaphylaxis episodes for the severity studies and 18,101 anaphylaxis episodes for the studies of new cases of anaphylaxis. BBs and ACEIs increased the severity of anaphylaxis (BBs, odds ratio [OR] 2.19, 95% confidence interval [CI] 1.25-3.84; ACEIs, OR 1.56, 95% CI 1.12-2.16), but not the presence of new cases of anaphylaxis (BBs, OR 1.40, 95% CI 0.91-2.14; ACEIs, OR 1.38, 95% CI 0.39-4.86). It was not possible to perform an analysis adjusted for cardiovascular diseases, because only 1 study each for BBs and ACEIs, respectively, had adjusted data., Conclusions: The quality of evidence showing that the use of BBs and ACEI increases the severity of anaphylaxis is low owing to differences in the control of confounders arising from the concomitant presence of cardiovascular diseases., (Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Reports of fatal anaphylaxis remain scarce because of the rarity of the condition and the fact that information is limited to a few countries., Objective: Our objective was to investigate clinical and demographic characteristics and the causes of fatal anaphylaxis in Spain using two databases of cases of fatal anaphylaxis., Methods: We analysed fatal anaphylaxis in a series from the Spanish hospital system and a series from the National Institute of Toxicology and Forensic Sciences (Instituto Nacional de Toxicología y Ciencias Forenses [INTCF]), which predominantly comprise extrahospital deaths. Deaths from the Spanish hospital system were retrieved from among all deaths occurring during 1998-2011 using codes related to anaphylaxis. Deaths due to anaphylaxis in the INTCF database during the same period were retrieved by 2 allergists, who identified cases in which anaphylaxis was a possible cause of death. A logistic regression model was constructed to predict the characteristics of fatal anaphylaxis in each database., Results: The incidence of death by anaphylaxis in Spain using both databases was 0.25 (95% CI, 0.24-0.26) deaths per million person-years. The most frequent causes of death in the hospital system were drugs (46.1%), unknown causes (40.0%), and foods (10.4%); in the INTCF, the most common causes of death were drugs (47.2%), insect stings (30.6%), and foods (11.1%). The logistic regression model showed that fatal anaphylaxis due to unknown causes (OR 15.2, 95% CI 1.8-129.8) was more likely in the hospital database, whereas insect stings (OR 100, 95% CI 10-833.3) and previous atopic comorbidity (OR 15.2, 95% CI 6.3-33.3) were more likely in the INTCF database., Conclusions & Clinical Relevance: The estimated frequency of fatal anaphylaxis in Spain was among the lowest reported. Future studies of fatal anaphylaxis should use databases from different origins in order to show the considerable heterogeneity in this type of death., (© 2018 John Wiley & Sons Ltd.)

Background and Objective: Studies assessing the severity of anaphylaxis lack a comprehensive approach to collecting data on comorbidities that may worsen prognosis. Objective: Using the Elixhauser score (a systematic index associated with longer stay, hospital charges, and mortality), we determined which comorbidities were associated with more severe anaphylaxis., Methods: We based our study on the Spanish Ministry of Health database of hospital discharges in Spain between 1997 and 2011. We constructed logistic regression models in which the dependent variables were outcomes related to greater severity (death, cardiac arrest, need for invasive mechanical ventilation or vasopressor drugs, admission to the intensive care unit, and length of stay) and the independent variables were the 30 comorbidities that comprise the Elixhauser score, age, sex, and main causes of anaphylaxis., Results: We found that a higher risk of severe anaphylaxis was associated (3 or more logistic regressions) with age >50 years or having experienced cardiac arrhythmia, coagulation disorder, associated fluid-electrolyte imbalance, chronic pulmonary disease, or Echinococcus anaphylaxis. Likewise, in the adjusted analysis, a higher Elixhauser score was associated with most of the outcomes analyzed for severity of anaphylaxis., Conclusions: Cardiovascular and respiratory diseases increase the severity of anaphylaxis, and the resulting poor health status (represented as a higher Elixhauser score) is associated with more severe anaphylaxis.

We report on trends in anaphylaxis admissions in the Spanish hospital system during the period 1998-2011. Data on admissions for anaphylaxis were obtained from the Spanish Information System for Hospital Data for the period 1998-2011. Patients were selected using the codes for anaphylaxis in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Poisson regression models were used to estimate incidence rate ratios. We recorded a 1.89-fold increase in admissions for anaphylaxis in Spanish hospitals during the study period, particularly in patients aged 0-14 years (1.65- to 3.22-fold until 2009 and 4.09- to 12.59-fold until 2011) and in food anaphylaxis in all age groups (2.78-fold until 2009 and 8.74-fold until 2011). The incidence of anaphylaxis is perceived as having increased in recent years, especially anaphylaxis caused by food and anaphylaxis affecting the pediatric population., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Knowledge about the epidemiology of anaphylaxis is based on data from various sources: clinical practice, large secondary clinical and administrative databases of primary care or hospitalized patients, and recent surveys with representative samples of the general population. As several similar results are often reported in several publications and populations, such findings are highly like to be robust. One such finding is that the incidence and prevalence of anaphylaxis are higher than previously thought. Publications from the last 5 years reveal an incidence of between 50 and 112 episodes per 100 000 person-years; estimated prevalence is 0.3-5.1% depending on the rigour of the definitions used. Figures are higher in children, especially those aged 0-4 years. Publications from various geographical areas based on clinical and administrative data on hospitalized patients suggest that the frequency of admissions due to anaphylaxis has increased (5-7-fold in the last 10-15 years). Other publications point to a geographic gradient in the incidence of anaphylaxis, with higher frequencies recorded in areas with few hours of sunlight. However, these trends could be the result of factors other than a real change in the incidence of anaphylaxis, such as changes in disease coding and in the care provided. Based on data from the records of voluntary declarations of death by physicians and from large national databases, death from anaphylaxis remains very infrequent and stands at 0.35-1.06 deaths per million people per year, with no increases observed in the last 10-15 years. Although anaphylaxis can be fatal, recurrence of anaphylaxis--especially that associated with atopic diseases and hymenoptera stings--affects 26.5-54% of patients., (© 2014 John Wiley & Sons Ltd.)

Background: Our objective was to ascertain the degree of adherence to recommendations made to patients with anaphylaxis, most of whom were attended in our allergy outpatient clinic., Methods: A questionnaire was sent to 1512 patients who had experienced anaphylaxis and completed by 887. The chosen definition of anaphylaxis was that of the National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network Symposium. We evaluated the prescription, purchase, and use of epinephrine auto-injectors and oral drugs, as well as the avoidance of allergens involved in previous anaphylaxis episodes., Results: Most patients (94.53%) reported that they had received advice on avoidance of responsible allergens after their allergy workup. Epinephrine auto-injectors and oral drugs were prescribed according to the subtype of anaphylaxis. Only 30.74% of patients used the epinephrine auto-injector; 54.26% took oral medication. Most patients (88.3%) avoided the allergen., Conclusions: Despite general agreement that anaphylaxis occurring in the community should be treated with epinephrine auto-injectors, use of these devices to treat recurrences was low in our patients. Oral medication intake was more common than the epinephrine auto-injector in all subtypes. In order to increase adherence to epinephrine auto-injectors, it is necessary to think beyond the measures recommended during regular visits to allergy outpatient clinics.

Background: Relatively few studies have examined the incidence of anaphylaxis in the general population., Objective: To report the incidence of anaphylaxis among the general population of the city of Alcorcon, Spain, using various public health care databases., Methods: Episodes of anaphylaxis were recovered using validated alphanumeric strings in different fields of electronic clinical records used in the different public health settings in the city of Alcorcon (primary care, Emergency Department, hospitalized patients and Allergy Outpatient Clinic). Patients with anaphylaxis were tracked across the different clinical settings in Alcorcon., Results: The incidence of anaphylaxis in Alcorcon was 103.37 episodes per 100 000 person-years (total standardized incidence rate of 112.2). There was a peak of 313.58 episodes in the 0-4 years age group and a different distribution of incidence rates (although non-significant) among different age groups between male patients and female patients. In most age groups, incidence tended to be higher for female patients aged over 10 years. Patients were attended at two or more levels in 76.78% of episodes, and a new evaluation was often made at a primary care centre (71.43%), Allergy Outpatient Clinic (75.6%), or both after the episode (58.93%)., Conclusion and Clinical Relevance: This study revealed a higher rate of anaphylaxis than that in previous studies, although this incidence rate is probably lower than the real incidence rate. Studies exploring potential methodological, genetic and environmental factors accounting for these higher rates of anaphylaxis are required., (© 2012 Blackwell Publishing Ltd.)

Background: The absence of large-scale international studies means that data on anaphylaxis in emergency departments in different geographic areas are still necessary., Objective: To determine the incidence of anaphylaxis and subtypes of anaphylaxis and their distribution by age group in the emergency department of Hospital Universitario Fundación Alcorcon, Alcorcon (Madrid), Spain., Methods: Our study was performed between 2004 and 2005. We used the definition of anaphylaxis established by the NIAID-FAAN Symposium. Patient information was collected from the electronic clinical records of the emergency department using alphanumeric strings to identify acute allergic illnesses. This strategy recovered 91.7% of all anaphylaxis episodes in a pilot study., Results: We observed a crude cumulative incidence of 0.9 episodes of anaphylaxis per 1000 emergency episodes (95% confidence interval [CI], 0.8-1.1), and 0.8 episodes per 1000 people (95% CI, 0.7-0.9). Standardized cumulative incidence of anaphylaxis according to the Standardized European Population was 1.1 (95% CI, 0.9-1.2). On analyzing the 213 cases of anaphylaxis, we discovered that the main cause was food (28.6%), followed by drugs (28.2%), unknown causes (27.2%), Anisakis (10.8%), Hymenoptera venom (3.3%), exercise (2.4%), and latex (0.9%). Food-induced anaphylaxis was less frequent in all groups older than the 0-4 age group in both reference populations (people who attend the emergency department and the general population)., Conclusions: The cumulative incidence of anaphylaxis in our emergency department is low. Anaphylaxis by foods is more frequent in the 0-4 year group than in the other age groups. Drugs and food are the most frequent causes of anaphylaxis in our emergency department.

Background: Only two studies have analyzed the incidence of anaphylaxis during admission to hospital. We have analyzed the incidence of anaphylaxis among hospitalized patients and determined the timing of and risk factors for episodes of anaphylaxis., Methods: Our study was performed between 1999 and 2005. We used the definition of anaphylaxis of the NIAID-FAAN symposium. Cases of anaphylaxis were extracted from an official database of discharge diagnoses coded according to the International Classification of Diseases, Clinical Modification, Ninth Revision (ICD-9-CM), Sixth Edition. Specific and generic codes related to anaphylaxis were chosen. This strategy revealed 83.3% (95% confidence interval, CI, 47-99%) of all episodes of anaphylaxis in a pilot study. The incidence of episodes of anaphylaxis and the hazard ratios were calculated for the different variables., Results: We observed a crude cumulative incidence of 1.5 episodes of anaphylaxis (95% CI, 0.9-1.9) in 5,000 admissions. The cumulative incidence according to the Standardized European Population was 1.6 cases in 5,000 admissions (95% CI, 0.8-2.3). Cox regression analysis showed that anaphylaxis occurs mainly in young people (0.97; 95% CI, 0.95-0.99) and its incidence differs according to the clinical unit. The Vascular Surgery Unit had the highest incidence rate (hazard ratio 7.7; 95% CI, 2.1-28.6). Males had a lower risk of suffering from anaphylaxis than females (0.5; 95% CI, 0.2-0.9)., Conclusions: Anaphylaxis is a very rare event among hospitalized patients. Female gender, young age and admission to the Vascular Surgery Unit favored the occurrence of episodes of anaphylaxis among hospitalized patients., (Copyright © 2011 S. Karger AG, Basel.)

Aims: We describe a rare case of anaphylaxis and thrombocytopenia whose cause was heparin used during hemodialysis sessions., Case Report: A 77-year-old woman suffered five consecutive episodes of vomiting, tachypnea, wheezing or rales, immediately after initiating hemodialysis. In the first of these episodes, arterial pressure was undetectable. In all of the episodes there was evidence of the presence of hypoxia (always below 60 mmHg) and thrombocytopenia (always below l00,000/microl,, with partial platelets recovery among episodes. The episodes started immediately after hemodialysis sessions and heparin infusion; either sodium heparin or enoxaparin was used. Utilization of different filters was not able to stop the episodes. These were stopped when a switch from heparin to hirudin was tested. Tryptase levels, as a marker of mast cells activation and anaphylaxis, were not increased in two of the episodes which were assessed. IgG antibodies against heparin-PF4 complex was detected at high levels., Discussion: A diagnosis of concomitant anaphylaxis and thrombocytopenia caused by sodium heparin and a low-molecular weight heparin (enoxaparin) were assumed.

Background: There are no studies assesing whether patients with idiopathic anaphylaxis are a heterogenous population, Objective: A study has been carried out to assess whether clinical and functional differences (mast cell releasability) exist between two sub-types of Idiopathic Anaphylaxis (Generalized Idiopathic Anaphylaxis -IA-G- and Idiopathic Anaphylaxis with Angioedema -IA-A-)., Methods: Patients were selected from the Idiopathic Anaphylaxis (IA) patient population of Hospital General de Albacete (Albacete, Spain) and this data were collected between 1990 and 1995. This series is composed of 81 patients. In the interest of seeing whether an IA classification is warranted between IA-G and IA-A, a logistic regression model was constructed in order to know if differences exist between IA-G and IA-A. To evaluate mast cell releaseability in different groups (IA-G, IA-A, atopic patients, urticaria and healthy subjects) we analysed the log 10 wheal area produced by four consecutive concentrations of codeine (from 90 to 3,3 mg/ ml). In those patients with IA-G, the variable urticaria was controlled, but not in those with IA-A. A parallel line assay was used to study the differences arising among all groups. When the conditions of parallelism and linearity were not fulfilled, a Hotelling's T2 test was performed., Results: In the logistic regression equation total IgE, with an O.R. of 1.006 (95% C.I. 1.001-1.01) favoured the presence of IA-G; whereas the presence of urticaria did not favour the presence of IA-G, with an O.R. of 0.159 (95% C.I. 0.04-0.507). IA-G and IA-A patients showed a higher cutaneous reaction to codeine than atopic patients (p=0.005 and p=0.001 respectively). However, IA-G patients had a lower reaction to codeine than those patients with urticaria (p=0.048). No differences were observed among patients with IA-A and patients with urticaria, as was the case between IA-A and IA-G patients with respect to cutaneous response to codeine., Conclusion: Apparently, IA-G patients appear to be closely related to the presence of atopy, while IA-A patients are closely related to the presence of urticaria. Along with other unknown factors, an enhanced mast cell releaseability may explain these episodes of Idiopathic Anaphylaxis among atopic patients.

Background: Few European groups have published data on series of patients with idiopathic anaphylaxis., Objective: Our aim was to report on our experience with this entity in Spain., Methods: We conducted a two-part investigation. The first part was a descriptive cross-sectional study of 81 patients with idiopathic anaphylaxis, diagnosed between January 1990 and December 1995 in the allergy unit of the General Hospital of Albacete in Albacete, Spain. The second prong was a prospective, longitudinal study that evaluated the activity of the condition., Results: Female patients constituted 68% of the study group with idiopathic anaphylaxis; the mean age of the 81 patients was 30.0 +/- 17.3 years. The number of episodes of idiopathic anaphylaxis during the year of greatest frequency varied widely (median, 2; range, 1 to 130). The duration also varied considerably, with a range of 0.03 to 300 months (median, 2 years). Most patients entered the study in remission, and 93% of these patients remained in remission throughout the followup period. Only 9% of the patients had vascular involvement. Our series of patients with idiopathic anaphylaxis had a notable prevalence of atopic diseases (48%), food allergy (20%), and episodes of anaphylaxis with an identifiable cause (15%). In addition, a high frequency (58%) of idiopathic urticaria was noted; the urticaria was acute in 62% of the affected patients., Conclusions: Our series of patients with idiopathic anaphylaxis is similar to previously published series.